The News
- NASA’s Chandra X-Ray Observatory went into safe mode as a result of a possible gyroscope failure.
Summary
- During the safe mode, scientific observations are interrupted.
- The orientation of the spacecraft is changed so that the solar panels get maximum sunlight.
What do gyroscopes do?
- In order to make precise observations of objects in space, pointing the telescope to an object and holding it steady is important
- This job is done by the gyroscopes and steering devices called reaction wheels.
- The gyroscopes help control the telescope’s pointing while scientists are observing the objects in space.
- Further when the telescope needs to be re-pointed to another object, the gyroscopes sense this and pass this message to the computer control system.
- The control system then a command to give the reaction wheels a “push” or “spin.”
About Chandra X-Ray Observatory
- The temperatures in various objects in space like starts, galaxies, supernova, blackhole etc are extremely high to the order of 10^6 to 10^8 Kelvin.
- Atoms in such a high-temperature gas move so fast that when they collide, they emit X-ray photons of very high energy and very short wavelengths less than 10 nm.
- Thus to study hot objects like inside of a star, supernova, centers of galaxies etc X-Ray telescopes are necessary.
- Further the X-ray photons in such short wavelengths do not enter earth because the earth’s atmosphere is opaque to them.
- Thus X-ray telescopes designed to detect these photons must be placed in orbit above earth’s atmosphere.
- X-ray astronomy took a quantum leap forward in 1999 with the launch of NASA’s Chandra X-ray Observatory.
- Chandra is named after the Indian- American astrophysicist Subrahmanyan Chandrasekhar.
- X rays are absorbed by mirrors and then reflected at a very shallow angle.
- In this way X rays are focused onto a focal plane 10 m behind the mirror.
- Thus Chandra can view the X-ray sky with an angular resolution of 0.5 arcsec wich gives sharp images of the object.
